Detective Jane Tennison must lift the lid on the most chilling murder case of her career to date. A coffin is dug up by builders in the grounds of an historic convent - inside is the body of a young nun. In a city as old as London, the discovery is hardly surprising. But when scratch marks are found on the inside of the coffin lid, Detective Jane Tennison believes she has unearthed a mystery far darker than any she's investigated before...